1. Field of the Invention
The present invention relates to a drive force transmission device, applied to the drive system of an electric vehicle, in which a motor and a transmission are separated by a divider wall.
2. Background Information
The drive system of a conventional hybrid drive force transmission device is provided with a motor disposed in a dry space within a motor housing and a belt-driven continuously variable transmission disposed in a wet space within a transmission case. Also comprised is a motor case that covers the outer periphery of the motor housing, is coupled to the transmission case, and forms an outer space between itself and the motor housing. An arrangement further comprising an O-ring that is interposed between the motor case and the motor housing and isolates the outer space and the wet space from each other is also known (see, for example, Japanese Laid-Open Patent Application No. 2010-151313, FIG. 7).